Channeling of roof water run-off is desired to minimize possible damage resulting from such run-off. Higher concerns may exist where rain water is channeled into a roof valley defined at the intersection of two or more pitched roof sections. The flow of water through a roof valley may be greater than other flows experienced on a roof due to the inherent concentrating effect of the roof valley's configuration. Flow exiting the roof valley, over the edge of the roof, may not fully pass into a gutter or leader due to its volume. Also, the roof valley discharge may overshoot the gutter or leader because of its inherent built-up momentum.
Devices have been developed in the prior art intended to divert roof valley rain water run-off into a gutter or leader. For example, U.S. Pat. No. 7,836,637 to Iannelli shows a valley diverter for a gutter cover. U.S. Pat. Nos. 6,009,672, 6,256,933 and 6,412,229, all to Kuhns, show a roof valley water collector.